Elevator.



No. (53|,7l0` Patented Aug. 22, |899. E. M. FRASER.

ELEVATOR.

Application mea June 19. 1899.,

\No Model.)

f' HVVE/VTOR.

me News Farias cu. pnorofumo.. wmmmm. n. c.

UNITED STATES PATENT OEEICE.

ETI-IELBERT M. FRASER, OF SAN FRANCISCO, CALIFORNIA.y

ELEVATOR.

SPECIFICATION forming part of Letters Patent No. 631,710, dated August 22, 1899.

Application filed J'nne 19, 1899. Serial No. 721,052. (No model.)

To rif/ZZ' wil/0711, t 11i/tty concern:

Be it known that I, ETHELBERT M. FRASER, a citizen of the United States, residing in the city and county of San1` Francisco, State of California, have invented an Improvement in Elevators; and I hereby declare the following to be a full, clear, and exact description of the same.

My invention relates to an improvement in elevators or hoisting-machines such as arev which will be more fully explained by ref-v erence to 'the accompanying drawings, in which- Figure 1 is a view illustrating one form of my device. Fig. 2 shows the parts separated for the clearer understanding of the operation.

The height or distance through which the elevator-cage and counterbalance-weights and connected parts are operated are necessarily shortened to comply with the limitations of the drawings; but it will be understood that these distances represent the heights of any building or wells or shafts in which the apparatus is designed to operate.

A is a car or equivalent device to be hoisted.

B is the rope or cable passing over a pulley C in the upper part of the shaft or space through which the cage is designed to move, and D is a counterweight with which the opposite end of the rope or cable is connected.

' This counterweight is'suitably proportioned to the weight of the car and to a second counterweight to be hereinafter described. These weights act in conjunction to balance the car and are so proportioned to each other as to divide the strain on the transmitting-ropes G G, as may be desired. Either Weight may be the heavier, the ettect on the car being the same. When the counterweight is drawn downward, the car is drawn upward. Vhen the counterweight is drawn upward, it correspondingly allows the car to descend.

The mechanism by which the car is operated consists of two independently-driven pulleys E and F and an endless rope or cable G, passing over said pulleys, thence in one direction over an idle pulley H,connected with the counterweight D, and in the other direction over'an idle pulley I, connected with a movable frame J. This frame has a rope K passing over a pulley'C in the upper part of the shaft, well, or hoistway, thence down to a counterweight L, which serves indirectly to maintain the tension of the ropes G. In practice these ropes G pass about the grooved pulleys, and may be as many in number as are required for the purpose.

The general operation of the apparatus is, as fully stated in my former patents, produced by the relatively different rates of circumferential speed of the driving-pulleys, and these pulleys E and F act through the ropes G and the connected parts to either raise or lower the car.

It Will be understood that the car, the counterweight, and the movable framework J are for convenience made to travel in suitable guides, which maintain them in their proper lines of travel; but these are omitted in the drawings in order toshow the special features of the invention clearly.

It will thus be seen that by means of the counterweight L an independent and indirect tension is constantly maintained upon the ropes G, and that no otherfspecial means for adjusting this tension is needed or any atten tion to the device.

As shown in Fig. 2, the cage and the counterbalances D and L are separated and independent of each other; but for convenience in operating and to economize space in which the part-s move I have shown a construction in Fig. 1 in which the frames D upon which the counterweight of the car is carried serve as guides for the independentlymovable counterweight L. These guides D' are of suf- Iicient length to allow for all necessary move- IOO the pulley H upon the counterweight D, and through this is' in direct connection with the car itself.

Having thus described iny invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The combination with independently- 2 operated pulleys, an endless cable thereon,

and a cage connected to and operated by said endless cable, of an automatically-operating tension device whereby the tension of saidcable is constantly maintained.

2. In an elevator, a car and counterweight therefor, and independently-operatiug drivin g-pulleys with an endless rope or cable passing around them connecting With and around i a pulley upon the counterweight, and alsoi around a pulley upon an independently-mow able frame, and an independently-actuatedi eounterweight connecting with said frame.

3. In an elevator, the' combination with a carer cage, a counterweight and a rope ,or cable passing over a pulley and connecting the weight and car, of independently-operated 2 pulleys with an endless cable driven thereby a rope passing from said second counterweight over a pulley and thence to a movable frame, in'combina'tion with independentlyactuated driving-pulleys, an endless rope or cable thereon and pulleys upon the main counterxveight and the frame around which said rope .or cable passes.

In Witness whereof I have hereunto set my hand.

lETIIELBEM" M. FRASER.

Witnesses:

S. H. NoURsE, J Essin C. lBuomn'. 

